提出一种不含有三光子脉冲的环回差分相位量子密钥分发(QKD)协议。 该协议可以在不需要监控信号干扰的情况下产生安全密钥,从而有效地降低实现的复杂度。此外,还提出了仅使 用两种强度的诱骗态去估计安全密钥生成率。实验结果表明该协议可以极大地提高安全密钥率,并增大传输距离。 而且,仅使用两种强度的诱骗态就可以获得接近使用无穷个诱骗态的性能,有效地减少了诱骗态资源的消耗。

A round-robin differential-phase-shift quantum-key-distribution (QKD) protocol without three-photon pulses is proposed. This protocol can generate a secure key without monitoring signal disturbance, thus effectively reducing the complexity of implementation. Moreover, two kinds of intensity decoy states are applied to estimate the key rate in the proposed protocol. The results show that the key rate of the proposed protocol is significantly improved, and the corresponding maximum transmission distance is also increased. In addition, as only two-intensity decoy states are needed to achieve the same performance as infinite decoy states in the proposed protocol, the consumption of decoy states are effectively reduced.